Worm gear screw hose clamps are very well known, the clamp being tightened or loosened by rotation of the worm gear screw in the respective direction, the rotation moving the tang to increase or decrease its degree of overlap with the remainder of the metal band and hence the periphery of the clamp. Several major problems may arise with this type of clamp. Some hose materials, especially silicone rubber materials, tend to extrude through the notches on tightening the clamp about the article being clamped. Such extrusions not only damage the hose but also tend to cause the clamp to stick and be difficult to loosen again when necessary. Hose extrusion also hinders other spring compensating clamps with the clamps ability to compensate joint fluctuation during thermal cycling. Another problem is associated with thermal changes. The changes in temperature create expansion and contraction of the hose, the fitting and the clamp. A number of attempts to compensate for thermal expansion during the operation of an assembled connection as well as to compensation for the aging or cold set of the hose itself have been attempted. A further problem is to maintain a fluid-tight seal throughout the intended life of the assembly, without requiring the clamp to be re-tightened.
It would be desirable to have a worm gear screw hose clamp that provides spring compensation to help overcome the hose shrinkage and expansion during thermal cycling, provides a liner that increases the clamp unit loading, and also provides a cover for the exposed notches in the band and will prevent any hose material from extruding through the notch area.